A process of manufacturing semiconductor substrates (hereinafter, simply referred to as “substrates”) has conventionally used a substrate processing apparatus that supplies processing liquids to a substrate that is being rotated, to perform various types of processing on the substrate. Such a substrate processing apparatus may include a cup part that is disposed around a substrate and receives, for example, processing liquids that are dispersed from the substrate by centrifugal force.
For example, a resist coating processor in Japanese Patent Application Laid-Open No. 2010-10251 (Document 1) has an exhaust port in the bottom of a processing cup. The processing cup has a canopy portion that extends radially outward from around a substrate. The gas above the substrate flows into the processing cup from clearance between the inner peripheral edge of the canopy portion of the processing cup and the substrate and is discharged through the exhaust port to the outside of the processing cup. The canopy portion has a plurality of vent holes in its outer periphery, and an opening-and-closing mechanism that covers and closes the plurality of vent holes from above is provided above the canopy portion. In the case of forming a resist film on the substrate, the opening-and-closing mechanism is moved upward and spaced from the canopy portion to open the plurality of vent holes. Thus, the gas above the substrate flows into the processing cup from the clearance between the inner peripheral edge of the canopy portion of the processing cup and the substrate and from the plurality of vent holes. As a result, the air current in the vicinity of the outer peripheral edge of the substrate is controlled, and the occurrence of a phenomenon in which a resist liquid stands up on the outer peripheral edge portion of the substrate is suppressed.
In a treating device for substrates disclosed in Japanese Patent Application Laid-Open No. 2010-10555 (Document 2), the internal space of a cup body is divided into an inner peripheral space and an outer peripheral space by a cylindrical movable partition body that extends upward from the bottom of the cup body. The movable partition body has an opening provided with a material that allows passage of gases but rejects passage of liquids (e.g., an air-permeable member made of fabrics or a porous material). When deionized water is supplied to a substrate, the movable partition body is moved down and located below the substrate, so that the deionized water drops into the outer peripheral space. The bottom of the outer peripheral space is connected to an exhaust blower via a gas-liquid separator, through which the deionized water dropped in the outer peripheral space and the atmosphere in the outer peripheral space are discharged to the outside of the cup body. When a chemical solution is supplied to the substrate, the movable partition body is moved up and located around the substrate, so that the chemical solution drops into the inner peripheral space. The atmosphere in the inner peripheral space is sucked into the outer peripheral space through the aforementioned opening of the movable partition body and discharged via the gas-liquid separator to the outside of the cup body.
A wafer cleaning device in Japanese Patent Application Laid-Open No. 2012-146835 (Document 3) has an air outlet and a drain outlet in the vicinity of the bottom of a spin cup. The wafer cleaning device switches between the air outlet provided in the vicinity of the bottom of the spin cup and an air outlet provided above the spin cup and the substrate in the side surface of a chamber. More specifically, a shutter that opens and closes the air outlet in the side surface of the chamber is provided and moved up and down in synchronization with up-down movement of the spin cup. At the time of conveyance of a substrate into and out of the chamber, the spin cup is moved down to close the air outlet provided in the vicinity of the bottom of the spin cup and to open the air outlet provided in the side surface of the chamber. In the case of processing a substrate with liquids, the spin cup is moved up to open the air outlet provided in the vicinity of the bottom of the spin cup and to close the air outlet provided in the side surface of the chamber. This mechanism keeps the internal pressure of the chamber almost constant.
In the devices disclosed in Documents 1 to 3, the same exhaust port or air outlet is used to discharge the atmosphere in the processing cup, even if the type of processing liquid used to process the substrate is changed. There is thus a possibility that, inside piping or the like connected to the exhaust port or air outlet, the atmosphere of a sucked processing liquid may be mixed with the atmosphere of other processing liquids remaining in the piping, causing undesirable mixing and interference of the processing liquids. The treating device in Document 2 may increase in size because the gas-liquid separator is provided outside the cup body as described above. Moreover, if adjustment of the flow rate of the gas exhausted from the exhaust port is required, the substrate processing apparatuses as described above may have a complicated structure and increase in size because a mechanism for adjusting the flow rate of the exhaust gas is provided in the exhaust pipe.